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{{ CSSRef() }}

Summary

The border-top-left-radius CSS property sets the rounding of the top-left corner of the element. The rounding can be a circle or an ellipse, or if one of the value is 0 no rounding is done and the corner is square.

If the value of this property is not set in a {{ cssxref("border-radius") }} shorthand property that is applied to the element after the border-top-left-radius CSS property, the value of this property is then reset to its initial value by the shorthand property.

{{ Xref_cssinitial() }}:0

Applies to: all elements

{{ Xref_cssinherited() }}:no

{{ xref_csspercentage() }}:yes, refer to the corresponding size of the border box

Media: {{ Xref_cssvisual() }}

{{ Xref_csscomputed() }}: the dimension of the semi-major and semi-minor axis, that is two absolute {{ xref_csslength() }} values

Is a {{ xref_csslength() }} or a {{ xref_csspercentage() }} denoting the radius of the circle to use for the border in that corner.

horizontal

Is a {{ xref_csslength() }} or a {{ xref_csspercentage() }} denoting the horizontal semi-major axis of the ellipsis to use for the border in that corner.

vertical

Is a {{ xref_csslength() }} or a {{ xref_csspercentage() }} denoting the vertical semi-major axis of the ellipsis to use for the border in that corner.

Values

<length>

Denotes the size of the circle radius or the semi-major and semi-minor axes of the ellipsis. It can be expressed in any unit allowed by the CSS {{ xref_csslength() }} data types.

<percentage>

Denotes the size of the circla radius or the semi-major and semi-minor axes of the ellipsis using percentages values. The percentage for the horizontal axe refer to the width of the box, whereas percentages for the vertial axe refer to the height of the box.

Browser compatibility

1.0 (1.0) {{ property_prefix("-moz") }} but with a non-standard name :-moz-border-radius-topleft

9.0

10.5

3.0 (522){{ property_prefix("-webkit") }}

4.0

4.0 (2.0)

5.0 (532.5)

Percentages

4.0

1.0 (1.0) with a bug (see note)

9.0

10.5

5.0 (532.5)

4.0 (2.0)

Elliptical corners

0.2

3.5 (1.9.1)

9.0

10.5

3.0 (522 )

Feature

Android

Firefox Mobile (Gecko)

IE Phone

Opera Mobile

Safari Mobile

Basic support

{{ CompatUnknown() }}

{{ CompatUnknown() }}

{{ CompatUnknown() }}

{{ CompatUnknown() }}

{{ CompatUnknown() }}

Browser notes

Gecko

The prefixed version (allowed from Firefox 1 to Firefox 13) of this property uses a different name, -moz-border-radius-topleft, than the final property as Mozilla implemented it before the final name was coined.

Until Firefox 3.6 included, the {{ xref_csspercentage() }} was relative to the width of the box even when specifying the radius for a height). This implied that -moz-border-radius-topleft was always drawing an arc of circle, and never an ellipse, when followed by a single value.